Fttse mechanism



WITNESSES:

ATTORNEY m m a t v n m w st Y M. J. SANDIN FUSE MECHANISM May 19, 1931.

Re. 18,073 s sneets-snet 2 Original Filed Oct. 25, 192

' WITNESSES: I

- INVENTOR Maur/b' J. 50nd? ATTORNEY M. J. SANDIN FUSE MECHANISM Re. 18,073 5 Sheets-Sheet 3 May 19, 1931.

Original Filed Oct. 25, 1921 INVENTOR Maur/fj U4 50nd? ATTORN EY Raced May 19, 1931 Re. 18,073 g new 3. mm, orwnxms'row vsmr, ALIEEGHENY country, rrmumvma.

ASSIGNOB TQfW'E STINGHOUSE ELECTRIC &

PORA'I'ION or rnmrsnvmu MANUFACTUBING.OOHPAFY, A. 003- I'USE MECHANISI Original 110. 1 584,518, dated September .18, 1928, Serial No. 510,280, 1led etober 1981. v Application for reissue filed September 17, 1880. Serial No. 482,680.

My invention relates to fuse mechanism and particularly to enclosed expulsion fuses.

One object of my invention is to provide an expulsion fuse that is adapted or use in 5 high-potential circuits of large capacity and which may be secured to vconductor-supporting poles. i

Another object of the invention is to pro vide a fuse mechanism, having the above characteristics, wherein replacementsmay be quickly and safely made,

Another object of my invention is to provide an expulsion fuse wherein the fusible element is caused to be ruptured near the closed end of the'receptacle and wherein the unfused portion of the fuse is blown bodily from the receptacle by the arc gases incident to the rupture of the fuse.

' Another object of my invention is to pro- -go vide an expulsion fuse that is equally efiec- Another object of my invention is to provide an expulsion fuse wherein the path of the arc is elongated between the terminals of the fuse and wherein tharc'may be drawn to substantially three times the length of the distance between the terminals .providing it is not previously extinguished, and wherein the cooling surface to which the arc. is exposed is co-extensive with its length.

Another objectof my inventionis to provide an expulsion cartridge fuse of rigid and durable construction that shall withstand repeated violent explosions without appreciable deterioration and in which a refillable fusible element may conveniently .sulatin Another object of my invention is to provide an expulsion fuse wherein a barrier is disposed betweenthe terminals of the fuse for preventing arcing from one terminal to another.

Another object of my invention is to rovide an ex ulsion fuse wherein a rigid intu surrounds the fuse and telescopica 1y fits within the main rece tacle and is supported by the outer end of t e fuse in such manner that, when the fusible element 1s ruptured 'within the insulating tube, are gases discharge therefrom to melt the retaining portion of the fuse, thusreleasing the tube and permitting it to Fe blown bodil from the receptacle and to increase the length of the arc in its movement out-of the receptacle.

A further object of my invention is to provide a housing for an expulsion fuse that is made princi ally of wood and wherein metal.-

bolts extending through the walls from edge to edge thereof serve both to join ad]'aoent walls and to prevent warping of the wooden parts; g

so and other objects that will be made:

e apparent throughout the further description of the invention, are attained by the expul 'sion-fuse construction hereinafter described, and illustrated in the accompanying drawin 5, wherein: p

igure 1 is a side elevational view of the complete enclosed ex ulsion-fuse mechanism, the side wall thereof show the construction of interior elements; Fig. 2 is a ,front' view of part of the app: ratus shown in .11, the cover and cartridge support ing removed; f Fig. 8 is am elevational view of afragment of ap aratus similar to that illustrated in- Fig. 1,

owing a modified door-latch constructlon; I

Fig. '1 isa n elevational view of tli'e'lfpsecartndge shown in Fig. 1; 5 Fi .5 is a lo itudmal sectional'view at the use cartridge shown in Fig. 4;

being broken away to Fig. 6 is an elevational view of afragment I of the fuse strip;

F' 7.is a side elev ionel View?! a modiiied orm fof 'fuse cartridge;

Figs. 8, 9 and 10 are elevational detail views of the locking mechanism for'securing the fuse cartri to its support;

Fig. 11 is-an evational new of a modified form of fuss mounting;

Fig. 12 is an elevational view of a modified form of'fus'e cartridge; and

Fig. 13 is a plan view of in Fig. 12. I v Bcfe to'the drawings, the apparatus includes a ousing preferably made of wood. and comprising a rear wall 14, side walls 15 and 16 and a bottom wall 17, all of which are he device shown made of wood, and a top wall 18 that comprises a flat pieceof metal having flanges 19 overlapping the side walls. The to wall of the x is inclined for the purpose 0 shedding water and is provided with an extension 21 havin attaching flanges 23'and 24' by means of w ch the box or housin may be secured to a wall. As illustrated, t e box is attached to a 8.111111 25 of adconductlogd supporting p0 not s own an is secu thereto by means of a lagbolt 26 which pro- 3 through aperforation in the extension 21.

- The side and backwalls are secured in assembledrelation with bolts 27 which extend through the back and bottom walls from one side of thebox to the other and the lower portion of the box is re-inforced-by metal plates 28 which extend slightly beyond the nt edges of the side walls to constitute hinge or the door, 29. The u ges of the. sidewalls are attac ed to the a r 1 of the top by means of short bolts 31. e door 29 is made of wood and is hinged to the bottom of the box by means of the hinge pin 32 which extends through the door from .one edge to the other and is mounted for rota tion in the projecting ends of the metal straps 28.- The bolts 27 and binge pin 32 prevent war in of the housing walls and the door.

e oor 29 is maintained in closed position by means of a movable latch handle 33 which is of U-sha of the box. The andle is pivotally, secured to the door bi means of a bolt 34 which extends throu the u per edge of the door from one si e thereo td'the otherand revents warping of the door. The free en of the latch andle 33 arerovided with latch projections 35"that are a apted to engage the open ner thatitherear faces of sto 36 that are. struck out wardly-from the ,anges 19- A A leaf spring 37 is riveted to the handle 33 and yieldingl engages the door in such manandle Itches35 are. yieldingly retained in engagement with the stops 36. To open the'door'the handle is-turned upwardly so that the latches 35: clear the stop members 36. Thedoor may thenbe movedto position; V

In Fig. 3, I have shown a modified form of liaudlestructurewhereinthelatch35isdismetallic bushing per front and straddles the sides,

more I posed above the stop member36 andis held in atching engagement. by spring 37 in a manner similar to that of the spring reviously described. In this case, t e han le is moved downwardly in order to release the latch.

The bottom 17 of the housin isprovided with a circular opening 38 in w ich an annular bushing 39, made of refractory material, such as porcelain, is inserted and retained in assembled relation with the bottom by means means of a leaf ofa split ring 41. The bushing 39 is provided with a. core 42 through which are gases may be discharged from the expulsion fuse, as will be hereinafter described. Referring particularly to Figs. 4 and 5,

wherein the referred form of expulsion fuse is illustrate the fuse mechanism includes a tubular receptacle 'or casin 43 made of micarta or any preferred insu atin materialof suflicient strength to withstand igh internal pressures. 7

Oneendof the casin endthereof is threads to receive a threaded 44 havin flat parallel side surfaces 45. T e other en of the bushing, is threaded to receive a closure or cap mem' er 46 which serves to securely close one end of the receptacle 43.

' A fuse terminal 47 is secured to the bushing \44 by means of a rivet 48 and is provided with a pair of clampin screws 49 upon which. a

clamping plate 51 is mounted for the pu ose of clamping a metallic fusible strip or use 52 to the terminal 47.

- The fuse strip comprises a flat strip of zinc or anypre erred fusible metal havin the desired oint of fusion which is provided with a portion 53 having a reduced cross section, as indicated in Fig. 6, and located at the point X, Fig. 5.

- ponthe open endof the receptacle 43 a contact bushing 54 isv mounted aving iiat parallel side portions 55. [A fuse-terminal member 56 is attached to thebushing 54 by means'of screws 57 and is provided, at one end, with anextension having a pair of clamping screws 58.

A clamping plate screws 58 which serves to clamp the outer end of thefuse 52 to the terminal 56 in a manner indicated .in Fig. 5. The terminal 56 is revidedwith a pair of win 61 that exten at right angles, from the ace of the terminal and are provided with aslot 62 having an enlarged circular portion 63 which serves as an element of aloeking device for securing the fuse receptacle to its support.

As shown n Fig. -5,*an insulating tube- 64,

which is preferably made of micarta, surrounds the fusible element 52 and telesco es within the receptacle 43 in such manner t at it may freely move longitudinally thereof. The tube 64 issu portedwithin the receptacle 43 bymeans of e lower end of. the fuse strip is open and the other.

59 is mounted on. the

52. The inner end of the fuse strip 52 is provided with a portion of reduced cross section within, and adjacent to, the upper end of the tube 64 for the pu ose of insuring that the fusible element wil fi-rst' rupture at the point X, causing the expansive, gases of the arc to first exert pressure at the closed end of the fuse and to blow toward the open end of the receptacle.

Under short-circuitconditions in a highcapacity circuit, the explosion is violent and is substantially Instantaneous. The gases are discharged from the receptacle 43 at a high velocity and impinge against an insulating sto member'65 that is secured to the outer en of the tube 641and causethe tube and the. remainingsolid ortion of the fuse strip 52 to be blown bodi y from the receptacle at a high velocity.

As the tube leaves'the receptacle, the arc incident tothe rupture of the fuse follows the end of the tube 64 and, therefore, elongates the arc and. so draws it way from the contact. sleeve 54 that it is extinguished before the tube actually leaves the receptacle. As the tube 64 moves through the receptacle 43, the arc within the tube and within the receptacle is expose'd'to an increasingsurface area which also assists to extinguish the are by reason of its cooling efiect. Q

By reason of this construction, the spark .is extinguished almost instantly after the rupture of the. fuse,.and no damage can be done to apparatus inthe circuit by reason of a'short-circuit' The provision ofthe tube 64 makes it possible to ractically instantly extinguish the arc inci exit to the rupture-of the fuse under overload conditions. It is a well known fact that, when a fuse is.ruptu'red under such conditions, arc gases are generated slowlyand, therefore do not generate high pressures.

Under overload conditions,.the arc has a tendency to gradually'melt the fusible element and the are is'sustained frequently between the terminals of the fuseafter-all of;

' the fuse has "been volatilize Such conditions are frequently disastrous to transformers and apparatus connectedin the circuit.

When the fuse illustrated in Fig.5 is rupunder overloadconditions, the fusible strip is first melted at the point X and the are gases are discharged from. the open end of the tube 64 which, in passing the outer end of the fuse strip 52, causes it to be melted aid-1 jacent the outer end of the tube 64.

The pressure within the receptacle, while not being as high as that ,.usually generated by a rupture caused by a short-circuit, is sufficient to blow the tube 64 bodil from the receptacle at a comparatively hig velocit and f thus stretch the arc circuit until it bre before the inner end of the tube 64 has left the receptacle 43. The solid strip between the point r and the outer end 86 having acircular opening 87 for receivin rtion ofthe fuse of the tube 64 is blown bodily "from the rece tacle with the tube 64.

eferring to Fi 1 and 2, the rear wall 14 of the housing or x is provided with an insulating panel made'of porcelain or other highl refractory insulating material and is attac ed to the housin by means of a bolt 66. The panel is provided with a lug 67 which projects into a socket 68' in the housing wall to prevent rotary movement of the panel about the axisof the bolt 66. Resilient fusejaw members 68 and 69 are attached to the panel 70, adjacent means of screws.

The fuse jaw members are provided with integral terminals 72 and 73 that are pro,-

vided with intersecting conductor ooves 74 for receiving the exposed ends 0 insulated conductors 75 which are secured to the terminals 72 and 7 3- by means of clamping plates 76 that are secured to the terminals by means of screws 77.

. The side walls of the housing are provided with inclined openings 78 through which insulating bushings 79 are inserted in aline ment with the intersecting grooves 74. By

reason of the provision of the intersecting grooves, 74 and the inclined openings 78, conductors may be led-into the ox side, the openings 78, not in use, being closed by means ofinsulatili plugs 81.

The door 29 is provided with an insulating panel '82 which is somewhat similar to the panel 70 and is secured to thedoor by means of a bolt 83. Rotation of the panel about the axis of the bolt 83 is prevented by a projection 84 on the panel which extends into a socket 85 in the door. The panel 82 is provided, at its upper end, with a bracket in Fig. 5. s

The lower end of the anel 82 is provided with a lockin device. see- Figs 1 2, 5, 8,

9 and 10). is device comprises a metallic bracket 88 having two wings 89 that project, at ri ht angles, from the face of the panel 82. The racket is attached to the panel b means of a bolt 91, and each wing is provi ed with a perforation 90 having. op ositely disposed arcuate surfaces 92 separate by angular projections-93, as illustrated in Fig.- 10.

. -A' flat latch bar 94' ofU-shapefhaving legs 95', is inserted .within the perforation 90 in a manner indicated-in Figs. 8 and 9. It will be seen that the latch bar 94 is'capable of angular-movement through 90, the extreme limits of movement being indicated in Fig. 9'by thefull-line position and the'dotted line position of the latch bar projections or legs 95.

The latch bar 94 is yleldingly maintained in either of its extreme positions b means of a flat s rin 96 of U-shape which is attached to the me at 88 and which extends between the bar 94- and the body of the bracket 88,

opposite ends thereof, by

from either the upper end of thefuse cartridge illustrate 2 shame in Figs. ems 9. n willbe that the rojections 93 serve as sto for limiting the angular movement of e latch 94. 4

When it is dedred to secure the fuse cartridge 43 to the panel 82, the closed end of the receptacle is passed through the opening 87 in the bracket 86. The latch V bar 94 is moved to the open position shown will enter in full lines in Fig. 9 wherein the edge of the bar. 94 is presented to the slot 62 in the atbracket 61. Therefore, the brackets or wings '82 until thebar 94 lies; within the circular 61 may be moved toward the base portion63 of the slot 62. The receptacle43 is then in its. bled relation with the support panel82 and is locked therein by sim-p y 'turni en the receptacle 43 is in assembled rela tion with the base 82, the flat surfaces 45 of the bushing 44 and the flat surfaces of the b 54 are in such positions that they.

68 and 69 respectively and be yieldinglyv en-' d thereby when the door is moved to wed-position, as illustrated in Fig. 1.

As t e door rotates about the hingepin 32,

' it will be seen that, when the door is closed,

' end, with a The barrier comprises a flatas micarta or other suitable insulating material the open end ofthe receptacle 43 rojects a short distance into-the opening42 o the bushing'39, thereby causing substantially all of the expelled from the fuse to be dischar through the opening in the bushing, the 'scharge serving as an ejector for air" and gaseswithin the box, thereby assisting to prevent the are .from flashing upwardly from the terminal bushing 44; I

While I have shown in 1, 2 and 5, a fuse construction in which eopejn end of the fuse receptacle projects only a ht distance into the bushing it is obvious at the of the receptacle me be extended to pro ect entirely within the' ushin and terminate flush with the outer en thereof. Such a fuse receptacle is illustrated in Fig. 7 and thence tacle is provided, at its o 11 ot 97 throu h whichthe v strip 52 projects from t e receptacle at a int between the ends thereof. By reason of this construction, no portion of the fuse strip 52 will project from the bushing and, co uently, there will be no danger of foreign o jects coming in contact therewith.

As a precaution against flare-back or a flash of from the open end of the receptacle to the terminals of the fuse, an insulatin'g'barrier 98 is inserted within the housing betweenthe fuse-jaw members 68 and 69. plate 98" of more 29 is in closed position.

tween the sides of the terminals that is provided, at its rear end with a flange 99 and a slot 101that extends from the front edge of the barrier rearwardly 'to the flange 99 in" such manner that thepanels and 82 are straddled by the barrier when the door The lateral edges 102 of the barrier are inserted in transverse ooves 103-cut in the side walls of the housing, and the flange 99 is mounted in a notch 104 provided in the rear face of the panel-70. By reason of this arrangement, no screws or bolts are required for securing the barrier in lace.

In order to entirely close t e space between the inner opposing faces of the anels 70 and 82, they are gral barrier-like extensions 105 and 106 that are provided with flanges 107- that overlap the inner edges of the all communication between the up r and lower portions ofthe housing. The arriers 105 and 106 meet at thelcentral longitudinal plane of the receptacle 43 and are provided with semi-circular notches 108 which when the door 29 is closed, as indicatedin si 1, combine to form a circular opening through which the receptacle 43 extends.

It will be seen from the foregoin that the box or housing is divided by. the arrier 98 and the barrier extensions 105 and 106 into a lower compartment containin' the lower fuse-jaw members and termina and an uparrier. 98 and close respectively provi ed withinte r compartment containing the upper. fuseaw members and terminals which, when the door is closed, are completely separated from one another and it is, "therefore, impossible for any ases flaring from the open end of the receptac e to be blown into the vicinity or.

make contact withthe upper terminals. When the fuse receptacle 43 is in assembled relation with the panel 82,. a shoulder 109 onthe bushing 44 e the bracket 86' in such manner that the recoil, incident to the explosion of the fuse, is absorbed by the bracket 86, and the fuse is thereby retained in operative position. I Referring to Fig. 11', I have shown an ex pulsion fuse somewhat similar in construction to the fuse previously described except i :that'the fuse is designed to be-mounted 1n the o n or in places where a housing is not ex ient or necessary. The'fuse 111' comprises a receptacle 112 having terminals 113 and 114 that are ada ted to be supported between fuse-jaw mem rs 115 and 116, res tively, The fuse-jaw members are attac ed to an insulating support 117.

The fuse strip 118 is provided with a portion 119 of reduced. sectional area that is disposed near the closed end of the cartridge, as shown in Fig. 11.

In order to prevent the arc, incident to the rupture of the fusible strip, from expanding Ill) outermost receptacle.

Jupport 117 near'the end of the fuse and casing open at one end only for the expulsion extends laterally in directions in a plane of arc gases and for enclosing the fusible transverse to the axis of the fuse. The size of the barrier may be varied in accordance with the capacit of the fuse.

In Fig. 12, I ave shown a modified form. of ex ulsion fuse wherein both ends of the] cartridge 122 are open and wherein a portion 123 of the fuse. strip 124, having a' reduced sectional area, is disposed mid-way between the openends of the cartrid This fuse is adapted to be inserted in use-jaw members similar to those illustrated in Fig. 11. y In order to prevent thearc ases, incident to the rupture of the fuse, whic are expelled L in this case from both ends .of the cartrid e, from expandin toward the terminals, a at barrier 125 ofcircular shape is secured to the cartridfge mid-way between the open ends thereo and serves to increase the length of the path between the termin-als'of the fuse. The diameter of thebarrier 125 may be varied in accordance with the capacity of the fuse;

While I have illustrated and described, several embodiments of mly invention, it will be apparent to those skil ed in the art that various changes, modifications, substitutions, additions and omissions ma be made in the ap aratus-illustrated wit out departing from e spirit and scope of myinvention, as set forth in the appended claims. i

i I claim as my mvention:

1. An e ulsion fuse comprisin a'tubular' receptacle osed at one end, a fusi le element. within the receptacle andsupported at opposits ends of the receptacle and having a portion adjacent the lower end thereof extending transversel across the mouth of the tube and in the pa of arc gases discharged from the receptacle whereby the end of the fuse ad'acent the open end of the rece tacle is fuse by are gases discharged from t 0 re 'ceptacle, a tubular shield surrounding the fusible member and supported within the receptacle by the fusible member and ineans for causing the fusible element to rupture at a predetermined point within the receptacle in ones toa predetermined. current.

2 2:! expulsion fuw comprising a plurality of relativel movable tu ular telescoping receptacles, t e outermost receptacle'being substantiall closed at one end andhav} ing its other en open to the atmosphere, and the innermost rece tacle being'open at both ends, and a fusib e element for releasably holding the receptacles in telescoped position and adapted to release theinterier receptacle when the fuse is ruptured, thes'aid element being provided adjacentits inner end with for localizing-the initial point of m I tureof the element near the closed end of t e 3. In combination, in an J ulsion fuse, a

i i of-se 'arate terminal mem' rs,"a fusible b element r connecting the member-s and a element, and adapted to be elon ated by the .arc gases incident'to rupture 0 "the fusible element, for increasing the length of the path of the arc between the terminals, the said fusible element being provided with means for insurin initial rupture thereof adjacent to the closed end of the casing.

4. The combination with ,a pair of separate fixed terminal members, a tubular casing having one end closed and a fusible element withinthe casing for connecting the terminal members and having means adjacent the closed-end of the casing for localizing the initial rupture of the element near the closed end of the casing, of a means including a tube open at both ends and disposed for longitudinal movement with respect to the casing for increasin the length'of the path of the are between t e terminal members. 7

5. An expulsion fuse comprising a tubular receptacle closed at one end, separate terminal members disposed at opposite endsof the rece tacle, a fusible element within the receptac e, a housing enclosing the receptacle and having an opening registering with the open 'end of the'receptacle through which are lgases are expelled and a barrier within the ousing and surrounding the receptacle and extending transversely, of the housing inter- *mediate the said terminal members.

6. A fuse device comprisinga tubular receptacle open to the atmosphere, separate terminal members disposed at opposite ends of the rece tacle, a fusible .element within the receptac e,.a housing enclosing the receptacle and a barrier extendin transversely of the housing between the said terminal members for preventing a flash-over between the terminals when are gases are expelled from the receptacle. y

' 7 An expulsion fuse device comprising a housing having a perforate bottom wall, a cover hinged'to the housing, a tubularbushing in the said 'opening and an expulsion fuse mounted on the cover and so disposed themon that the open end ofthe fuse projects into' the said bushing when the door is in closed position. H

8. An expulsion fuse device comprising a housing having a hinged door for the housin an ex ulsion fuse mounted on the door an provi ed with-separateicontact members, separate terminal members mounted in the housing for engaging the contact members on the fuse when the door is in closed position and a barrierdisposed transversely of the housin'g,between the said terminal members and surrounding the said fuse.

"9. An enclosed expulsion fuse comprising a housing, a movable door therefor, an insulating panel mounted in the housing having a arrier member projecting therefrom, separate fuse" jaw members mounted on' the housing and an e elndlltkl'll as -12.An

mentwithinthereee IF fuseisruptured.

the an el,a fuse-supporting panel. mounted on e door and having a bamer projecting therefrom adapted to register with the'bar-- rier on the first panel,'an. expulsion fuse mounted upon thesecond panel and adapted to be surrounded by the said barriers when the door is in closed position, a third bar- I -rier secured to thehousing and adapted to co-operate with the first and second barriers for constituting a transverse barrier for dividing the housing into separate compartments, each containing one of the said sop rate terminal members.

u113i. Thfolszombination an enclosloid1 on comprlsmg a ousmg, a

oorfor the housing, fuse-jaw terminals ulsion fuse mounted on the. door and move is into enent with the fuse-jaw terminals, of a vpair of co-opera'ting "barrier m em one o which'is secured within the housing and the other secured to the door for constituting a closed barrier between the said fuse-yaw members when the door is in closed position.

a memberha asocketmem rdispoeedat' oneendthereo andasup ,rtcomp a basemember a perforate iii -rzfiet thereon for one endof the fuse in the perforation to prevent lateral displacement thereof, and a latch member on'the supportv for engaging'the socket member on the fuse for preventing both longitudinal lacement. of the fuse.

lar rece eclosed at one end, terminal members 'fomthe receptacle, a; fusible ele- .ingtherece ean havinganopenmgre m the open end of thereceptace 513" usual husm' g a rner m e 0 an surroun tfllie rl-leceptacle and extending transversely o e ousmgr 13. An expulsion-fuse device com rising a housing having a hinged door for e housan expulsion fuse mounted-on the door 'bers, separate terminal members mounted in the; housing. for enfia the contact member'sonthefusew en edoorisinclosed position anda barrier disposed transversely of the housing and surrounding the said fuse.

'14. An ulsion fuse compri a plurality of re atively movable tub telereceptacles, one of which is when y osed at one endandha the other end'open to the atmosphere and s 0 which is open at both-ends and a fusible element havin ,means for initial-m ture thereo adjacent the cl ed to release the second receptacle w "race he enclosing the endacent theo" 11. Fuse mechanism comprising n fuse comprising-a-tubu .of the expulsion fuse, an

a housing enclos-,-

which are gases are expelled and a:-

provided with separate contact mem-r arranged in arallel re ation and ha end of e- I first receptacle for' releasably hol the receptacle in telescoped posit on andhen more.

cally slidable tubes the outer tube being open atone end only and the inner tube mally open to the atmosphere, a pair of sgacedterminals mounted on the outside of t e outer tube, a fuse element passing through the innertube and having its outer end secured toa terminal and its inner end provided with a means for insuring rupture of the element adj acentthe closed end of the outer tube, the premure of gas within the 15. A fuse comprisinga pair oftelescopiopen 'at both ends and having its outer en norinner tube produced by'the volatilization of i said element causing the outer end portion of the inner tube to move out 'of'the outer tul e and positively interrupt the circuit; 7

- 1 6. An e ulsion a tubular (gle.

other .end,'-terminal members for the rece f tacleya' fuse element the-recap e andconnectedtotheterminalmembers,1

recetacleopenatthe of the receptacle and a barrier wi the housing between 2:: 'ends of the receptacleandsurroun the housing.

l7. An e'x'pulsion fuse device a housing having a movable door an .havmg an o e' at one end, an expulsion fuse within the housfi having itsopen and ad-- jacent the open of the housing and provided witha member, a transverse barrier the housing between the ends a transverse bar riot-carried by the door with first'saidbarrier to constitute a transverse ulsionlfuae for rfrom arc and barrier surrounding the l' hd a r a gases m e open en 0 e expulsioh se 1 18."-An expulsion comprising-a pair of .terminalmembers, a air of tubular casings adjacent one another,

having h i op n an and a fusible element connecting the ,terminalsiand through the casings and receptacle and osed atone end and open at the out across the adjacent open ends of the tubular casings, so that heated gasesexpelled fromacasingwillmove across the 1 portion of the fusible element and w on it at thatpoint, the said element having means for localizing the" oint of initial rupture and near e closed end'of, one of e casings. I 19. An expulsion fuse comfprising a par of terminal members, a air 0 tubular cflifilgi air 0' ends a jaoent one another, and a ends of the tubular-casing so that beats sible ve ement of substantially U-shape connecting. the terminals and extending through the cas-' ings and out across the adjacent 0 gasesex-' pelledfromacasingwillmoveacrosstheex-' posed portion of the fusible element and weaken it at that point, the said element having means for localizing the point of initial K rupture within and near the closed end of one of the casings. V a

- 20. An expulslon' fuse comprisin a tubular receptacle closed at one end an open at the other end, a terminal for the closed end of the tube, a. housingenclosing the receptacle and open at the en adjacent the open end ofthe receptacle, and a barrier within the housing between the, open endof-the receptacle and the said terminal and surrounding the receptacle and extending transversely of the'housln 21. Ahousing-for anj expulsion fuse ro-.

15 tided with a door, a receptacle mounte on said door and a fusible element within said receptacle and extending beyond the confines 'of said housing.

22. A housin for an expulsion fusehav- 2o ing a perforate bottom and a door, a tubular receptacle mounted'on the door, spaced contact members associated with said rece tacle, s aced terminal members moun on said ousing en geable with said contact members and a sible element within said receptacle and extending beyond the confines of the housing. 23. A housing for an expulsion fuse prov vided with an o ning in one walland with a so door, a receptac amounted on said door and a fusible element within saidrece ta'cle'; and said recep1tacle having an open en extending beyond t e inner edge of the housing at its 4 wall openin p I 3e 24. In a circuit interrupter, a housing hav-.

inga bottom wall with an opening therein, a door hinged to said housing ad acent said bottom wall,a fuse receptacle having an open end mounted on said door so that said open end extendsjinto said 0 ning in the bottom wall when the door-is c osed.

25. In a circuit interrupter, a housing having a bottom wall with an-opening therein, spaced terminal members in said housing, a

45 doorhinged to said housing adjacent said bottom wall, a fuse receptacle having spaced contact members to engage said terminal members, said rece tacle having an o n end and bein mount 'on said door'so at said so open en extends. into said '0 ning in the bottom wall when the door is c osed. e Intestimony whereof,Iha ve hereunto sub.-

' scribed my name this 16th day of September,

66' J. SANDIN. 

